Java中怎么使用RSA加密算法，针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。
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代码如下
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
public class RSADecrypt {
public static Map createKeyPair() throws NoSuchAlgorithmException {
//创建秘钥对生成器
KeyPairGenerator generator = KeyPairGenerator.getInstance("rsa");
//初始化密钥对生成器
generator.initialize(1024);
//生成密钥对
KeyPair keyPair = generator.generateKeyPair();
//获取公钥私钥
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
String publicKeyStr = new String(publicKey.getEncoded());
String privateKeyStr = new String(privateKey.getEncoded());
//公钥私钥存放map
Map keyMap = new HashMap<>();
keyMap.put("publicKey", publicKeyStr);
keyMap.put("privateKey", privateKeyStr);
return keyMap;
}
/**
* 获取公钥
* @param publicKey
* @return
*/
public static RSAPublicKey getPublicKey(String publicKey) throws NoSuchAlgorithmException, InvalidKeySpecException {
KeyFactory keyFactory = KeyFactory.getInstance("rsa");
//X509编码
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getBytes());
RSAPublicKey rsaPublicKey = (RSAPublicKey) keyFactory.generatePublic(x509EncodedKeySpec);
return rsaPublicKey;
}
/**
* 获取私钥
* @param privateKey
* @return
*/
public static RSAPrivateKey getPrivateKey(String privateKey) throws NoSuchAlgorithmException, InvalidKeySpecException {
KeyFactory keyFactory = KeyFactory.getInstance("rsa");
//PKCS#8编码
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getBytes());
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyFactory.generatePrivate(pkcs8EncodedKeySpec);
return rsaPrivateKey;
}
/**
* 公钥加密
* @param src
* @param publicKey
* @return
*/
public static byte[] publicEncrypt(String src, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
Cipher cipher = Cipher.getInstance("rsa");
cipher.init(Cipher.ENCRYPT_MODE,publicKey);
byte[] encryptedData = cipher.doFinal(src.getBytes());
return encryptedData;
}
/**
* 私钥解密
* @param data
* @param privateKey
* @return
* @throws NoSuchPaddingException
* @throws NoSuchAlgorithmException
* @throws InvalidKeyException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
*/
public static String privateDecrypt(byte[] data, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
Cipher cipher = Cipher.getInstance("rsa");
cipher.init(Cipher.DECRYPT_MODE,privateKey);
byte[] result = cipher.doFinal(data);
return new String(result);
}
public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchPaddingException {
Map keyPair = createKeyPair();
RSAPublicKey publicKey = getPublicKey(keyPair.get("publicKey"));
RSAPrivateKey privateKey = getPrivateKey(keyPair.get("privateKey"));
String str = "hello world";
/**
* 公钥加密，私钥解密
*/
byte[] encryptedData = publicEncrypt(str,publicKey);
String result = privateDecrypt(encryptedData, privateKey);
/**
* 私钥加密，公钥解密
*/
byte[] encrypted = privateEncrypt(str, privateKey);
String source = publicDecrypt(encrypted, publicKey);
}
/**
* 私钥加密
* @param src
* @param privateKey
* @return
* @throws NoSuchPaddingException
* @throws NoSuchAlgorithmException
* @throws InvalidKeyException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
*/
public static byte[] privateEncrypt(String src, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
Cipher cipher = Cipher.getInstance("rsa");
cipher.init(Cipher.DECRYPT_MODE,privateKey);
byte[] result = cipher.doFinal(src.getBytes());
return result;
}
/**
* 公钥解密
* @param data
* @param publicKey
* @return
* @throws NoSuchPaddingException
* @throws NoSuchAlgorithmException
* @throws InvalidKeyException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
*/
public static String publicDecrypt(byte[] data, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
Cipher cipher = Cipher.getInstance("rsa");
cipher.init(Cipher.DECRYPT_MODE,publicKey);
byte[] result = cipher.doFinal(data);
return new String(result);
}
} 上面例子使用密钥长度1024，如果想使用2048密钥，只需要在初始化密钥对生成器做一些变动，其他部分可以复用。
generator.initialize(2048);
关于Java中怎么使用RSA加密算法问题的解答就分享到这里了，希望以上内容可以对大家有一定的帮助，如果你还有很多疑惑没有解开，可以关注创新互联行业资讯频道了解更多相关知识。
